====== PP 350 ======
Calibre **PP 350** (and the similar **PP I-350**) is an [[automatic]] watch movement from [[Patek Philippe]]. It was the industry's first [[peripheral rotor]] automatic movement, used from [[1970]] through [[1985]].

===== Info =====
Cal. 350 was a highly innovative movement on its introduction, with a bi-directional [[peripheral rotor]] for automatic winding and back-mounted stem and crown. This technology had been patented in [[1955]] by [[Gosteli, Paul|Paul Gosteli]] but never produced. However, this unconventional winding system proved unreliable, even after a [[1979]] re-design with uni-directional winding, the Cal. **I-350**. This too proved problematic and the entire series was retired by [[1985]].

Cal. 350 featured a [[free-sprung]] [[Gyromax]] balance, 28 jewels, and earned the [[Geneva Seal]].

Cal. 350 has a poor reputation today, but its problems are likely over-stated. The short life was likely due in major part to the unconventional location of the crown on the back of the watch, an arrangement that did not match most watch models. Patek Philippe also found success with [[PP 240|Cal. 240]], still in production today, [[PP 315|Cal. 315]], and [[PP 27-460|Cal. 27-460]].

===== Cal. I-350 =====
Calibre I-350 (for "Improved") was introduced in [[1979]] to fix the issues associated with Cal. 350. The major difference is the replacement of the bi-directional winding system with a uni-directional gear. About 10,000 I-350 movements were built and used by [[1985]].

===== Applications =====
  * [[Patek Philippe Calatrava 3563]]
  * [[Patek Philippe Calatrava 3569]]
  * [[Patek Philippe 3573]]
  * [[Patek Philippe 3585]]
  * [[Patek Philippe 3586]]

===== See also =====
  * [[PP 12-600 AT]], the predecessor
  * [[PP 315]], the successor

===== External Links =====
  * [[http://watchguy.co.uk/service-patek-philippe-calibre-350i|Service:|Patek Philippe calibre 350i]]

<WRAP ud ud_mov>
**Description:**
  * [[Automatic]] movement with [[peripheral rotor]]

**Functions:**
  * Hour/minute/second hands

**Data:**
  * 21,600 A/h

**Production period:**
  * [[1970]]-[[1985]]
</WRAP>

{{tag>Movements Automatic_movements Patek_Philippe_calibres}}